Internal-combustion engine cooling system



Aug w. w. MUIR ,4752

INTERNAL-COMBUSTION ENGINE COOLING SYSTEM I Filed Sept. 15, 1945 2 Sheets-Sheet l Fla/0 LEVEL FL 0/0 L EVEL A. 19480 W. w. MUIR 2,4752

INTERNAL-COMBUSTION ENGINE COOLING SYSTEM Filed Sept. 13, 1945 2 Sheets-Sheet 2 duits i and it. said by-pass having therein a thermostatically controlled valve is for stopping the flow of fluid from conduit is to the pump,

thereby cutting oil the cooling eilect of the radiator 1. Hence, when the engine is started in cold weather, this thermostatic valve will be closed wherefore the circuit for the cooling fluid will comprise merely the engine jacket and the by-pass conduit id, but as the temperature of the cooling fluid increases, the thermostatic element of the valve is will be affected by this rise in temperature, and will cause said valve to open, thus permitting the pump 6 to draw fluid from the radiator by means Oi conduit l8 and hence subject the heated cooling fluid to the cooling action or said radiator. A drain cock 2! is provided at the lowest point or the system.

It a car' heater is to be operated bythe heated cooling medium, the same may be connected to the cooling system as by the pipe connections indicated in dotted lines at 2i and 22 to the by-pass conduit it, or any other desired part of the system.

In order to maintain this system liquid sealed. there is provided a tank or reservoir 80 the bottom oi which is connected as by the unrestricted conduit St to the,upper manifold 8, this conduit being devoid of any valve or other restriction, and preferably being of relatively small internal diameter, such for example as inch tor the usual automobile cooling system. This tank is so disposed that when the system is completely filled with fluid through the filler pipe i i, the fluid level in the tank will be approximately as shown in the drawings, leaving an airchamber 32 above such level and which air chamber is vented to the atmosphere as by the vent pipe 83. That is to say, the. tank has no filler opening or, stated in other words, it is a normally closed tank into which the fluid is passed by virtue of the flller pipe ii and conduit 8!, the fluid rising in said tank until the level thereof corresponds to the level of the illler pipe. air escaping from the tank through the vent 31. In Fig. 1 the conduit II is illustrated as joining the conduit ii at the upper manifold I. The bottom of the tank 10 may be in the same horizontal plane with the upper m'anitold I, or slightly elevated with respect thereto, but in no instance should it be below said manifold. It is the reservoir of fluid in said tank which" operates under the law of gravity to maintain the system liquid-sealed under all conditions oi ensine operation.

Thus it will be understood that the system when fllled with fluid will be a completely closed system, with the fluid disposed therein and in the tank is up to the level created by the upper end of the filler pipe H, whereupon no air will be in the system, but there will be air in the upper portion-oi tank 80 above said fluid level. As the engine is operated, the temperature of the cooling fluid will rise, the fluid first being circulated mechanically by the pump through only the bypass conduit l8 and then. at higher temperatures. additionally through the radiator I when the thermostatic control is employed. This circuit will never include the tank ill and the fluid therein, nor will it include the fluid in conduit 8| between said tank and its juncture with conduit l5. It thus results that the temperature of the fluid in conduit II and tank 30 is but slightly afl'ected by the temperature rise in the true cooling circult, or in other words there will always be a relatively large dlirerential or temperature between ill! and the fluid oi the tent;

Upon higher temperatures being attained. vapors and/or steam may be generated in the cooling circuit in the locality oi the Jacket 5. which vapors will rise and pass in circuit to the juncture of conduits it and 8!. It the flow of the cooling fluid in the cooling circuit remains substantially constant, the pressure in manifold 9 and conduit 3! will be equal in magnitude, and there will be no how of fluid or vapor from manifold 9 to conduit 3!. The flow oi fluid and vapor will be irom manifold d to tubes 8, by virtue or the pump 6.

0n the other hand, i: the flow of cooling fluid in the cooling circuit is abruptly reduced when the power output from the engine is high, vapor pockets will iorm in jacket 8 and displace part of the cooling fluid. The displaced cooling fluid will cause the pressure in manifold t to increase above the pressure in conduit 3i, and this difference in pressure will cause fluid and vapor to flow from manifold a to conduit 3i and the reservoir til. The duration of how will vary lrom thirty-one seconds to two minutes in time. When this how from manifold t to conduit ill has subsided, the how will be reversed i. e. from reservoir to manifold B in order to replace the fluid which was displaced by the vapor pockets in jacket s. The formation oi vapor pockets in jacket 3 when the how or cooling fluid is abruptly reduced, is caused by the lag in heat transfer from the engine cylinder 2 to thecooling fluid in Jacket 3, and this lag will vary from thirty-one the fluid or the circuit as.

,- seconds to two minutes. depending upon a number of variable conditions. Therefore it is to be understood that the reservoir 30 acts as a surge absorber and a vapor condenser.

Obviously it the engine is abruptly stopped, when the power output therefrom is high, the surge in the cooling system will be greater than if the flow in the cooling circuit was abruptly reduced. When the surge occurs, the temperature of the fluid in the reservoir will increase, and at the same time the volume of fluid in the reservoir will increase. when the surge subsides the temperature of the fluid in the reservoir will decline, and also the volume of the fluid in the reservoir will become reduced.

It the flow oi cooling fluid in the cooling circuit remains substantially constant, and the radiation from radiator 1 to the air remains substantially constant, all oi. the vapor in conduit ill and manitold I will be condensed in the radiator tubes I. The only time that vapor will flow from the maniiold to the conduit II is when a surge occurs in the cooling system. Inasmuch as this system is a liquid gravity sealed cooling circuit, its operation is diflerent from the down-flow system where free air is present in the upper part 01' the top tank on the radiator. The volume or the iluid in tank iii is infinitely greater than the volume in filler pipe H, wherefore there is little or no danger of the fluid level ever becoming lowered accldentally to the plane oi conduit Ii.

The cover over the automobile engine, commonly referred to as the hood, is represented at 34, and 3d designates the vertical partition extending downwardly from the hood to form the cowl. The tank 30 may be provided with a top opening, ora covered opening at the bottom th'ereoi, to provide for cleaning the tank as and when necessary.

The same principles are present in the modiilcation illustrated in Fig. 2, the difference residing only in st: va etal details. Here the conduit 8! from the tank to is shown joining the filler pipe H at a. point just above the upper manifold 8, the conduit I5 passing directly from the engine jacket 3 to said manifold, and the thermostatic valve, by-pass conduit and drain cock have been omitted from Fig. 2 to reduce the invention to its simplest form of illustration.

It is-obvious that those skilled in the art may vary the details of construction and arrangements of parts constituting the apparatus, as well as vary the steps and combinations oisteps-constituting the method oi cooling without departing from the spirit of this invention wherefore it is desired not to be limited to the exactioregoing disclosure except. as may be required by the claims.

What is claimed is:

1. A'cooling system for an internal combustionengine provided with a cooling jacket, comprising a downilow radiator, a pump. and fluid-conducting connections between said jacket, said radiator and said pump for establishing a cooling circuit, a tank for cooling fluid maintained at a level above the cooling circuit and connected to the circuit to provide free gravity feed of the fluid in said tank to the circuit,. and means for filling the circuit and a portion of said tank at a-point remote from said tank.

2. A cooling system for an internal combustion engine provided with a cooling jacket, comprising a downflow radiator, a pump, and a fluid-conducting connection between said jacket, said radiator and said pump for establishing a cooling circuit, a tank for cooling fluid maintained at a level above the cooling circuit, a fluid-conducting conduit connecting said tank and the circuit to provide gravity feed of the fluid in said tank to the circuit, means for venting the system at the coldestportion thereof, said means including a portion oi said conduit, and means for filling the circuit and a portion of said tank at a point remote from said tank.

3. A cooling system for an internal combustion engine providedwith a cooling jacket, comprising a downfiow radiator, a pump, and fluid-- conducting connections between said jacket, said radiator and said pump for establishing a cooling circuit, a tank for cooling fluid maintained at a level above the cooling circuitya vent for the system connected to the coldest portion of said tank, a fluid-conducting conduit connecting said tank and the circuit, said conduit serving to conduct vapors travelling toward said vent as well as serving as a gravity feed for the fluid flowing from said tank to the circuit, and means for filling the circuit and a portion of said tank at a point remote from said tank.

4. A cooling system for an internal combustion engine provided with a, cooling jacket, comprising a downflow radiator, a pump, and fluid conducting connections between said jacket, said radiator and said pump for establishing a cooling circuit, a tank for cooling fluid maintained at a level above the cooling circuit, a vent for the system connected to the coldest portion of said tank, a fiuid conducting conduit connecting said tank and the circuit, said conduit serving to conduct vapors travelling toward said vent as well as serving as a gravity feed for the iluid flowing from said tank to the circuit, and means for filling the circuit and a portion of said tank.

5. A cooling system for an internal combustion engine provided with a cooling jacket, compris= ing a downfiow radiator, a pump, and fluid con prising a radiator and fluid-conducting connec' tions between. said jacket and said radiator for establishing a cooling circuit, a reservoir of cooling fluid delivering to the'hot sideoi' the circuit, and means for venting the system at the coldest portion thereof.

'L'A cooling system for an internal combustion engine provided with ,a-cooling jacket, comprising a radiator and fluid-conducting connections between said jacket and said radiator for establishing a cooling circuit, a reservoir of cooling fluid for the circuit, and a conduit between an upper portion 0! said radiator and said reservoir, said conduit serving as a free gravity I 'feedior the fluid from the reservoir to the circuit, as well as serving to conduct vapors from the circuit to said reservoir for condensation therein.

8. A cooling system for an internal combustion eng ne provided with a cooling jacket, comprising a radiator and fluid-conducting connections between said jacket and said radiator for establishing a cooling circuit, a reservoir of cooling fluid {or the circuit, and a conduit between an upper portion of said radiator and said reservoir, said conduit serving as a gravity feed for the fluid from the reservoir to the circuit, as well as serving to conduct vapors *from the circuit to said reservoir for condensation therein, and means for venting the system at the coldest portion thereof.

9. In a cooling system for an internal combus tion engine provided with a cooling circuit for the cooling fluid, the combination of a tank for holding a quantity of the cooling fluid, said tank disposed above the cooling circuit and having a single unrestricted conduit leading from the bottom portion of the tank to the upper portion of the circuit for conducting cooling fluid in one direction and vapors in the opposite direction.

10. In a cooling system for an internal combustion engine provided with a cooling circuit for the cooling fluid, the combination of a tank for holding a quantity of the cooling fluid, said tank disposed above the cooling circuit and having a single conduit leading from the bottom portion of the tank to the upper portion of the circuit for conducting cooling fluid in one direction and vapors in the opposite direction, and means for venting the system-at the coldest portion thereof.

11. The method of cooling an internal combustion engine provided with a cooling circuit through which a cooling fluid may be circulated, which comprises establishing a reservoir of the cooling fluid, conducting the cooling fluid from such reservoir to the hot side of the circuit, and subjecting all vapors formed in the circuit to the action of the conducted fluid for condensation reservoir to the hot side of the circuit, subjecting vapors formed in the circuit to the action of the conducted fluid for condensation thereof, and venting the system at the coldest portion thereof.

13. The method of cooling an internal combustion engine provided with a Jacket which comprises creating a cooling circuit for a cooling fluid through such jacket, establishing a reservoir of the cooling fluid, conducting the fluid from such reservoir to the upper portion of the circuit, and causing all vapors formed in the circuit to be condensed by contact with the conducted fluid.

14. The method of cooling an internal combustion engine provided with a jacket which comprises creating a cooling circuit for a cooling fluid through such jacket. establishing a reservoir of the cooling fluid, conducting the fluid from such reservoir to the upper portion of the circuit, causing all vapors formed in the circuit to be condensed by contact with the conducted fluid, and maintaining the fluid in such reservoir at a temperature much lower than the operating temperature of the fluid in such circuit.

15. The method of cooling an internal combustion engine provided with a Jacket which comprises creating a cooling circuit for a cooling fluid through such Jacket, establishing a reservoir of the cooling fluid, conducting the fluid from such reservoir to the upper portion of the circuit, causing vapors formed in the circuit to be condensed by contact with the conducted fluid. maintaining the fluid in such reservoir at a temperature much lower than the operating temperature of the fluid in such circuit, and venting the cooling system at the coldest portion thereof.

16. A cooling system for an internal combustion engine having a cooling circuit comprising a down-flow radiator and a reservoir of cooling fluid disposed at a level above said circuit. the reservoir connected at its bottom to the upper portion of said radiator by a substantially horizontal conduit, the system being vented at the coldest porin the circuit will be condensed in their passage through said conduit in contact with the cooling fluid therein.

17. An all-liquid cooling system for an internal combustion engine provided with a cooling Jacket, comprising a radiator and liquid-conducting connections between said jacket and said radiator for establishing a cooling circuit, and a reservoir of liquid delivering unrestrictedly to the hot side of the cooling circuit.

WELLINGTON W. MUIR.

REFERENCES CITED The following references are of record in the ills of this patent:

UNITED STATES PATENTS France 1923 tion of the rservoir whereby any vapors formed 

